Question

What do you understand by elevation of boiling point?

Hint:

The elevation of boiling point is a colligative property, meaning it depends on the number of solute particles, not their identity.

Answer 1

Step 1: Define Elevation of Boiling Point.
The elevation of boiling point refers to the increase in the boiling point of a solvent when a non-volatile solute is dissolved in it. This phenomenon occurs due to the reduction in the vapor pressure of the solvent, which requires a higher temperature to reach the boiling point.
Step 2: Explanation.
When a non-volatile solute is added to a solvent, it lowers the vapor pressure of the solvent because the solute particles occupy space on the surface of the liquid, thereby reducing the number of solvent molecules escaping into the vapor phase. As a result, the solvent must be heated to a higher temperature to achieve the necessary vapor pressure for boiling. The relationship between the elevation in boiling point (\(\Delta T_b\)) and the amount of solute is given by the equation: \[ \Delta T_b = K_b \times m \] Where: - \( \Delta T_b \) is the elevation in boiling point. - \( K_b \) is the ebullioscopic constant (a property of the solvent). - \( m \) is the molality of the solute.
Final Answer: The elevation of boiling point is the increase in the boiling point of a solvent when a non-volatile solute is added, caused by the lowering of vapor pressure.
Final Answer: \[ \boxed{\text{The elevation of boiling point is the increase in the boiling point due to the addition of a non-volatile solute.}} \]